One of the most famous Swiss engines is the Ae 6/6, the mighty Gotthardlok especially built to tame the demanding Gotthardbahn.
50 years later, despite being mostly superceded on the Gotthard line by the Re 6/6, those rugged engines still remain in service.
The Rail Simulator version will hopefully come in all its various appearances, with the chrome finished Kantonsloks in red and green for starters.
Cab and sounds shall be made as well, but i haven't even started on them yet...
If you're able to understand the German language then read more on those engines on the truly fantastic website of SBB Driver Bruno Lämmli.